Vegetation of six Carolina bays in Maryland.

Abstract

Vascular plant communities in six Carolina bays in Maryland were classified using stratified-random plot sampling of presence and cover in conjunction with BrayCurtis Polar Ordination and Sorensen's Index of Dissimilarity. Species diversity and annual cover differences also were analyzed during the two-year study period of 1987-1988. Collectively, five zonal community types were identified in the ground layer. The most frequent type, dominated by Leucothoe racemosa Gray, was restricted to the forested perimeter. The Carex walteriana Bailey (C. striata Michx.) community occurred as an interlying zone near or contiguous with the forested perimeter and as the sole non-perimeter community. Panicum hemitomon Schult. only occurred as a narrow band near or adjacent to the forested perimeter. Rhexia virginica L. and P. verrucosum Muhl. communities were restricted to the innermost non-perimeter zone. Species diversity and annual differences in cover generally increased from perimeter to center. Leucothoe racemosa, P. hemitomon, and C. walteriana communities, restricted to drier portions of the gradient, had lower values for these parameters than the more mesic R. virginica and P. verrucosum communities.